Arc lamp



J. GELB ARC LAMP Aug. 29, 1939.

Filed June 1, 1955 ATTORNEY Patented Aug. 29, 1939 UNHTED STATES ARC LAIHP Joseph Gelb, New York, N. Y.

Application June ii,

18 Siairns.

The. present invention is concerned with a functionally and structurally improved arc lamp of the type having means for maintaining the arc gap defined by cooperating electrodes substantially constant during effective operation of the lamp. The invention has as one of its objects the provision of pivotally interconnected bell crank levers for supporting a pair of electrodes substantially in horizontal axial alinement. The invention has as another object the provision of means for supporting a pair of electrodes and an equalizing spring for counter balancing the weight of the supporting means. The invention further contemplates the provision of electrically controlled means for holding and uniformly moving the electrodes towards each other in accordance with the wear of the electrodes. The invention has as a further object the provision of a tiltable reflector adjustable relative to a pair of horizontally disposed electrodes, Further features, objects, and advantages of the invention are in part obvious and in part hereinafter more fully pointed out.

The invention accordingly comprises the features of construction, combination of elements, arrangement of parts, which will be exemplified in the construction hereinafter set forth and the scope of the application thereof will be indicated in the appended claims. 7

Thepresent invention will be best understood from the. following specification, reference being made to the accompanying drawing in which Fig. 1 is a vertical elevational view of the arc lamp according to the invention, partly illus trated in section.

Fig. 2 is a fragmentary view of Fig. 1, but showing the arrangement of the parts after the electro magnet has been energized.

Fig. 3 is an enlarged side view of an electrode holder according to the invention.

Fig. 4 is a sectional view on the line 4-i of Fig. 3 and Fig. 5 is a view taken on the line 55 of Fig. 1, shown on a. larger scale.

Referring to the drawing, the supporting means for the lamp, generally designated A, comprises a post it to which is rigidly secured a sleeve I! having a yoke i 2 fixedly supporting a horizontally disposed elongated shelf [3.

Extending upwardly from shelf l3 and appropriately secured thereto is a pair of spaced brackets i i and I5. Bracket 35 rotatably sustains a pair of fulcrum pins l5 and il respectively carried by bell crank levers l8 and !9. The upper portion 20 of bell crank lever I8 is 1935, Serial No. 24,483

provided with a fulcrum post 2! straddled by a forked or bifurcated end of upper portion 2?. of cell crank lever l9, hence forming an overlapped pivoted or rocking connection. Set screws adjustably associated with standard l5 cooperate with a respective fulcrum post as E6 to hold the latter in proper relation in respect to its supporting bracket i5.

Bell crank lever i3 is provided with an angularly offset extension it having an arcuate depending flat sided arm 25 which is movably guided in slot 26 of a block 27 removably carried by an extension 28 projecting from bracket l4 and by an offset extension 28 projecting from bridge plate 3G common to and integrally interconnecting spaced brackets l4 and iii.

A solenoid or electro-magnet 31 is mounted on the bridge 30 and the latter embodies a suitable opening in which armature 32 of the solenoid is slidably moved. Armature 32 is provided with diverging legs 33 to each of which is attached one terminal of a curved shock absorbing spring 3 3 having vertically juxtapositioned portions 35 forming an eye 36 closely but movably surrounding a transversely disposed fulcrum pin 37 carried by spaced arms 38 of a yoke broadly designated 39 having one end pivotally associated with bracket 54 and its other pivotally connected to the reciprocable cylinder or jacket Ail of a dash pot, generally denoted 4!.

Dash pot 4! comprises a piston 42 preferably of carbon, to which is attached piston rod 42', disposed at an incline in respect of the vertical axis of the solenoid, and pivotally and swingably associated with lug 43 projecting from shelf Swingably associated with yoke or link 39 is a yoke or link 44 to the upper portion of which is connected an irregular shaped shock absorb ing spring 45 comprising a laterally disposed portion connected to a clutch or brake 36 having a vertically disposed opening 4? having flat sides adapted to frictionally engage the sides of archate arm 25 and to lift the latter when armature 32 is retracted.

spending from shelf i3 is a pair of spaced arms 18 each of which terminate in an annular eye or socket $9 each having a horizontally closed and circular horizontal face 59 slidably cooperating with an annular overhanging flange E-i projecting from the crown portion 52 of a canopy or reflector housing, generally designated 53. An axially perforated disc 54 rigidly secured to sides of crown portion 52 is provided with an annular flange 55 which supports an associated annular flange the arrangement being such that the canopy may be rotated or tilted relative to the bell crank levers l8 and I9 and held in a desired tilted position due to the continuous frictional engagement of faces 50 of eyes 49 and the exterior horizontal annular faces of the overhanging flanges 5!.

Appropriately insulated and suitably carried by each of bell crank levers I8 and I9, is an electrode holder, generally designated 55, in each of which a carbon electrode 51 is slidably supported. Each electrode holder has a pair of laterally disposed perforated lugs 58 and 59 each attached to the clamping arrangement embodying a hollow bolt 60 comprising a circular perforated head GI and an integrally connected hollow shank 62 surrounded by a disc shaped washer 53, and a sleeve 64. Also surrounding hollow shank 62 is a disc shaped washer 65, the washers 63 and 65 together with sleeve 64, being preferably of a suitable insulation, for example, mica, forming an annular insulated channel in which spaced lugs 66 of an extension El depending from a bell crank lever is removably clamped by rotating nut 68 threadedly interconnected with a respective shank 62. If desired, a metal but relatively thin washer may be interposed between the mica washer 65 and nut 68 and a set screw 69 is utilized to adjustably clamp the head 6| of the bolt against adjacent lugs as 59, and if desired, a metal washer may be interposed between the head of set screw 69 and the nut 63. It is apparent therefore that each bell crank lever removably carries a horizontally disposed electrode holder appropriately insulated therefrom.

Rotatably carried by each electrode holder is a manually controlled crank H having an eccentric 12 adapted to either raise or lower movable clamping jaw 73. If raised, an electrode 51 may be slidably adjusted relative to its holder. If lowered, electrode 5'! is firmly gripped in its holder and prevented from longitudinal displacement.

Rigidly attached to each lower portion of the bell crank levers is a hollow cylindrical drum s appropriately spaced from depending extensions 6'5 thereof. A drum i4 may be grasped by the operator to manually displace the bell crank levers when the power is removed from cable connected to a suitable electro motive force. Since the electrode holders are insulated from. the bell crank levers, it follows therefore, that drums 14 are also insulated from the electrode holders.

Cable '15 has its leads [6 and 17 electrically connected respectively to the spaced binding posts 78 and 39 carried by bracket Hi. Conductor 85 connects binding post 18 with one pole of solenoid 3!, while conductor 3! is connected to binding post 19 and one of the electrodes 51, the conductor Bl being appropriately confined in a longitudinally disposed groove 82 in the long arm of bell crank lever l8. Connected to the other pole of solenoid 3! is the conductor 84. This conductor is confined in a groove 85 of the long arm of bell crank lever l9 and is electrically connected to electrode 57 carried thereby.

As illustrated in Fig. l, solenoid 3! is in a series circuit with the contact points of the opposing electrodes 5'l. If, electric power is supplied to conductors 8!] and 8!, the solenoid becomes energized and its armature 32 is retracted. Consequently link 38 is raised which in turn lifts yoke or link Mi and the latter through spring 45 raises clutch 46. I Now, since the walls of slot 41 are disposed at an incline relative to the sides of the arm 25, the walls of slot Ml coact with the sides of the arcuate arm. to lift and hold the latter in an elevated position. Accordingly, arm is swung upwardly, and the bell crank levers i8 and i9 are simultaneously swung outwardly until clutch 46 strikes adjustable stop pin 86 carried by extension 28.

With the bell crank levers swung outwardly, the electrodes are separated and form an arc travelling gap, the distance of the gap varying in accordance with the displacement of the clutch or brake 46 away from associated supporting block 27. Hence by regulating the position of stop pin 86, the gap distance between the electrodes may be controlled.

Interconnecting shelf l3 and a shorter arm of one of the bell crank levers is a vertically disposed counter balancing spring S'l. rlormally spring 8'! is distended, for example, as indicated in Fig. l and in effect balances the combined weight of the pivotally interconnected bell crank levers l8 and I9, and accordingly the weight of these arms is not transmitted to the armature of the solenoid. It follows therefore that when the armature is retracted, the bell crank levers quickly separate since the load of the bell crank levers is absorbed by the equalizing and counter balancing spring 81.

With the solenoid energized and the electrodes separated to form the predetermined arc gap, the poles or inner ends of the electrodes wear away, consequently causing a condition which would increase the size of the gap, but since, the

armature of the solenoid gradually drops due to the reduction of the strength of its magnetic field, the distance of the arc gap is maintained substantially constant until such time that the clutch 45 in lowering strikes block 2'5, at which time, clutch 45 frees or rel-eases arcuate arm 25 for a split second, causing the bell crank levers to move towards each other a slight distance, consequently decreasing the size of the gap thus reducing the internal resistance of the circuit and the solenoid is revitalized. It follows that the armature, again, is retracted, permitting clutch 46 to raise arouate arm 25 for diverging the electrodes to form the predetermined sized gap. This cycle of operation continues periodically and it is therefore appreciated, that with the present arrangement, although the arcing points of the electrodes wear away, provision is made for maintaining the arc gap substantially constant.

It will be apparent that the rays of light emanating from the electrodes may be adjustably directed by merely rotating canopy reflector 53, and further that the feed of the electrodes is automatically and horizontally controlled, the swivel or rotatable connection between the canopy and the spaced arms 43, permits the canopy to be tilted substantially one hundred and eighty degrees about the electrodes if rotated in one direction and substantially one hundred and eighty degrees if rotated in a counter direction.

Where uniform and even distribution of light is desired, a diffusing plate 89 may be provided. This diffusing plate is of a suitable glass and may be appropriately supported within the canopy between a pair of washers Qii adjustably controlled by a stud 9!.

As is well understood a suitable casing (not shown) may be mounted on and secured to shelf l3 to enclose the upper portion of the control means and the bell crank levers above the shelf.

For purposes of specification, the control means may be broadly considered as directed to the solenoid and the parts actuated thereby with the exception of the bell crank levers and the equalizing spring, while the supporting means may be generally considered as directed to post l0, shelf 13, the spaced brackets l4 and I5, and the spaced depending arms 48.

In the broader aspects of the invention, I do not desire to be understood as limiting its embodiment to details herein described and shown illustratively as a wide variety of modifications may be made within the scope of the appended claims without departing from the spirit of the invention.

I claim:

1. In an arc lamp, the combination of, supporting means, a reflector secured to said supporting means, holders having means for removably sustaining a pair of electrodes substantially in axial and horizontal alinement, horizontally spaced and vertically arranged pivotally interconnected bell crank levers swingably carried by said supporting means, spring means connected to said supporting means and at least to one of said levers for equalizing the combined weight of said levers, electrically controlled means for actuating said levers to separate said electrodes to define an arc gap, and adjustable means to limit separation of said electrodes.

2. In an arc lamp, the combination of, supporting means, a tiltable and adjustable reflector having a rotatable connection with said supporting means, substantially horizontally disposed hollow holders having means for removably and adjustably sustaining a pair of electrodes in axial and horizontal alinement, opposing and pivotally interconnected bell crank levers insulated from and supporting said holders and swingably carried by said supporting means, a normally distended and substantially vertically disposed spring interconnected with said supporting means and one of said levers to counterbalance the weight of said levers, electrically controlled means for diverging said levers to separate said electrodes and means to limit said separation.

3. In an arc lamp, the combination of, supporting means, an adjustable reflector rotatably carried by said supporting means, substantially horizontally disposed holders having means for removably and adjustably sustaining a pair of electrodes, vertically arranged pivotally interconnected swingable bell crank levers insulated from and connected to said holders, a normally distended spring interconnecting at least one of said levers and said supporting means for counter balancing said levers, and electrically controlled means for spreading said levers to separate the electrodes of said holders to define an arc gap, said electrically controlled means hav ing means for maintaining said gap substantially constant.

4. In an arc lamp, the combination of, supporting means, an adjustable reflector rotatably sustained by said supporting means, substantially horizontally disposed holders having means for removably and adjustably sustaining a pair of electrodes, substantially vertically arranged pivotally interconnected swingable bell crank levers insulated from and connected to said holders, a normally distended spring for counter balancing said levers and electrically controlled means for spreading said levers to substantially horizontally separate said electrodes to define an arc gap, said controlled means comprising a clutch and restraining means to automatically permit said levers to slightly approach each other to compensate for wear of said electrodes and maintain said gap substantially constant in length.

5. In an arc lamp, the combination of, supporting means, an adjustable reflector said supporting means and reflector having means defining a rotatable connection to permit rotation of said reflector relative to said supporting means, substantially horizontally disposed holders having means for removably and adjustably sustaining a pair of electrodes, pivotally interconnected vertically arranged bell crank levers pivotally carried by said supporting means and insulated from said holders, a normally distended spring interposed between said levers and said supporting means to counter balance the weight of said levers, and electrically controlled means for actuating said levers to separate adjacent portions of said electrodes.

6. In an arc lamp, the combination of, companion and substantially vertically disposed bell crank levers, an extension depending from each lever and comprising spaced lugs each having an opening, a bolt embodying a shank projecting through an opening of said lugs and a head spaced from said extension, an electrode holder, insulating means interposed between said head and extension and said shank and the walls of one of said openings, a clamping member adjustably connected to said shank, an insulating washer interposed between said member and extension, and a clamping instrumentality passing through said shank and removably interconnected with said holder.

7. In an arc lamp, the combination of, companion and substantially vertically disposed bell crank levers, an extension depending from each lever comprising spaced lugs each having an opening, a hollow bolt associated with each opening including a shank disposed in and in part projecting beyond a respective opening of said lugs, and a head spaced from said extension; an electrode holder, an insulating washer interposed between said head and extension, an insulating sleeve in part surrounding said shank, a clamping member adjustably mounted on said shank, an insulating member interposed between said extension and clamping member, and a clamping instrumentality in part disposed within the bore of said shank and having a portion removably interconnected with said holder.

8. In an arc lamp, the combination of, supporting means, a pair of bell crank levers each comprising a relatively long and short arm and having their short arms pivotally interconnected and disposed at the upper portion of said supporting means, a horizontally disposed shelf, said bell crank levers having their long arms extending downwardly and below said shelf and outwardly in respect to their short arms, each of said long arms having an extension, an electrode holder removably secured to each extension and insulated therefrom, spaced arms depending from said shelf and each including a socket, a reflector having means rotatably and frictionally connected to the sockets of said spaced depending arms, said sockets forming passageways to permit bodily displacement of said holders upon actuation of said bell crank levers, and spring means connected to at least one of saidshort arms and to said shelf to counterbalance the weight of said bell crank levers.

9. In an arc lamp, the combination of, supporting means, a pair of bell crank levers each comprising a relatively long and short arm and having their short arm pivotally interconnected and disposed at the upper portion of said supporting means, a horizontally disposed shelf, said bell crank levers having their long arms extending downwardly and below said shelf and outwardly in respect to said short arms, a holder insulated from and carried by each of said long arms and each having means for supporting an electrode and disposed substantially horizontal during inoperative electrical periods of said electrodes, spaced arms depending from said shelf and including sockets to receive said holders, a shiftable reflector having means frictionaly and rotatably supported by said sockets, means for swinging said arms outwardly and laterally relative to said sockets, and spring means connected to said shelf and to at least one of said short arms to balance the weight of said bell crank levers.

10. In an arc lamp, the combination of, supporting means, a reflector carried by said supporting means, substantially horizontally disposed holders having means for removably and adjust-- ably sustaining a pair of electrodes, substantially ;matically permit said levers to slightly approach each other against the resistance of said spring to compensate for wear of said electrodes and maintain said gap substantially constant in length.

11. In an arc lamp, the combination of, sup-- porting means, a reflector sustained by said supporting means, holders having means for removably and adjustably sustaining a pair of electrodes, pivotally interconnected swingable bell crank lever insulated from and connected to said holders, means secured to said supporting means for pivotally sustaining said levers, a, normally distended, spring for counter balancing said levers, electrically controlled means for spreading said levers against the resistance of said spring to compress the latter and separate said electrodes to define an arc gap, said controlled means comprising a clutch and restraining means to automatically permit said levers to slightly approach each other to compensate for wear of said electrode and maintain said gap substantially constant in length, and stop means to momentarily release said clutch.

12. In an arc lamp, the combination of, supporting means having a shelf, vertically arranged and pivotall interconnected bell crank levers swingably connected to said supporting means and in part extending above and below said shelf, an electrode holder secured to each lever and extending laterally thereof, a reflector disposed below said shelf and carried by said supporting means, and means for counterbalancing said levers.

13. In an arc lamp, the combination of, supporting means having a shelf, bell crank levers pivoted to said supporting means and each comprising a relatively short and a relatively long arm, means above said shelf and pivotally con.- necting said short arms to permit said long arms to extend substantially vertically and downwardly to project below said shelf, said long arms having lower terminals, a reflector, substantially horizontally disposed electrode holders secured to said terminals and insulated therefrom, an insulated lever carried by each holder to permit adjustment of the electrode supported thereby, and means for counterbalancing said levers for normally permitting said holders to be in part pro-- jected into said reflector.

14. In an arc lamp, the combination of, supporting means, an adjustable reflector having a rotatable connection with said supporting means, holders extending laterally of said reflector and each having means for supporting an electrode, pivotally interconnected swingable means pivotally carried by said supporting means and insulated from said holders, spring means interconnecting said swingable means and said sup porting means for counterbalancing said swingable means, and control means to diverge said swingable means to separate said electrodes and having a circuit in series with said electrodes.

15. In an arc lamp, the combination of, supporting means, a reflector sustained by said supporting means, electrode holders having means for removably and adjustably sustaining a pair of electrodes, substantially vertically arranged and horizontally spaced bell crank levers comprising relatively long arms insulated from and connected to said holders and relatively short arms, means secured to said supporting means for pivotally sustaining said levers, conterbalancing means for said levers and connected to said short arms, means pivotally interconnecting said short arms, and controllable means to operate said levers to spread said long arms against the resistance of said counterbalancing means.

16. In an arc lamp, the combination of supporting means, a reflector disposed below said supporting means and having a downwardly facing crown, substantially horizontally arranged electrode holders, substantially vertically disposed and horizontally spaced bell crank levers pivotally secured to said supporting means above said reflector and comprising relatively long arms insulated from said holders and relatively short arms pivotally interconnected, and counterbalancing means connected to at least one of said short arms and said supporting means.

17. In an arc lamp, supporting means, a reflector having a rotatable connection with said supporting means, opposed electrode holders extending laterally of said reflector, swingable means pivotally carried by said supporting, means and carrying the'said holders, counterbalance means operatively connected with said swingable means, and control means to actuate said swingable means to separate the holders.

18. In an arc lamp, supporting means, spaced members depending from and secured to said supporting means, each member having a terminal bearing member, swingable arms carried by said supporting means, the arms having means for holding a pair of electrodes substantially in horizontal alignment, and a tiltable reflector having portions rotatably received by said bearing members, said reflector having a portion to receive adjacent parts of said electrodes.

' JOSEPH GELB. 

